Muffler



May 13, 1958 L. D. MASON MUFFLER Fild Nov. 8, 1954 INVENTOR. Lindon D. Mason ATTORNEY United States Patent -MUFFLER Lindon D. Mason, Denver, Colo., assignor to Nu-Flo Products, Incorporated, Littleton, C010,, a corporation of Colorado Application November 8, 1954, Serial No. 467,251

4 Claims. (Cl. 181-557) This invention relates to mufilersof the general type commonly associated with and to receive the exhaust gases from internal combustion engines for thecooling and silencing of the exhaust prior to its release to atmosphere, and has as an object toprovide an improved such muffler characterized by enhanced efficiency in thecooling and silencing of engine exhaust without the development of adverse back pressures.

A further object of the invention is to provide an improved simple and efiicient organization of elements constituting an exhaust gas mufiler for internal combustion engines.

A further object of theinventionis to provide a novel and efficient exhaust gas rnufiler susceptible of production from readilyavailable components with facility and economy.

A'further object of theinvention is to provide an improved exhaust gas muftier susceptible of expedient production in a variety of particular sizes and forms adapted to :functionefiiciently with variousmakes, types, and sizes of internal combustion engines.

With the-foregoing and other obiects in view, m y invention consists infthe construction,arrangement, and operative combination of elements as hereinafter set forth, pointed out'inmy claims, and illustrated bytheaccompanyingdrawing, in Which- Figure 1 is a side elevation ofa typical mufllerembodyingthe principles of rny invention, 1a portionof the view beingbroken awayto illustrateotherwise concealed relationships.

igu 2 i as c o l n anen at e sca e takm tudinally and axially throughlhcorganigation according to'Figure 1, an intermediateportion of the view being broken away to conserve space.

Figure '3 is .a cross section taken substantially on the indicated line 3-3 of Figure 2.

Figure 4 is a cross section taken substantially on the indicated line. 44 of Figure 2.

Figure 5 is a section similar to Figure4 illustratinga modification of form Within the contemplation of the invention.

Figure 6 is asection similar to Figure A illustrating an alternative modification of form within the contemplationof the invention.

Mufllers, in a wide variety of particular formssand constructions, are extensively inuse with and to cool and silence ,the exhaust discharge from internal combustion engines. Satisfactory performance .of such mufflers is measured by their effectiveness in cooling and silencing the exhaust passed therethrough without the generationof adverse back pressures and is to some extent related to the-useful life of the muffler under the heats and corrosive influences to which it is subject, hence an important consideration in the production and use of mufflers is economy of manufacture and replacement with operative elliciency. The extensive use of diesel-type engines in automotive vehicles and the peculiar difliculty encountered in the cooling and silencing of the exhaust from such engines has r 2,834,426 .P te e a 3.,

2 introduced a situation for which hitherto conventional mufi lers have appeared to be inadequateor unduly expensive of maintenance and replacement, hence the instant invention is directed to theprovision of a novel and improved rnufiier operable with enhanced efficiency and with low cost of production and replacement to cool and to efiectively silence internal combustion exhaust gases.

Simulative of conventional practicein the production of mufilers, the improvement includes astraight, elongated, hollow and imperforate shell10 closed at its opposite ends by-means of plates 11 and 12, and provided with an inlet pipe 13 centrally intersecting the plate lland an outlet, or tailpipe, 14 centrally intersecting the plate 12. The exposed end of the inlet pipe 13 is worked-in any conventional or, expedient manner, asto the'form of 1 a radially-enlarged socket 15, for connection with and to receive the output from an engine exhaust gas line or manifold 16, and the exposed end of the tailpipe14 may discharge to atmosphere directly. or may engage withcontinuations and extensions thereof leading to a preferred point of ultimate discharge, all as is customary practice. Regardless of any working of their exposed portions, the inlet pipe 13 and the tailpipe 14 are, as represented, straight and unobstructed in a bore size and capacity at least-equal to that of the exhaust gasline or manifold 16, thus to inhibit the generation of increased pressures as the flow traverses said pipes in enteringandin leaving the shell 10, and said pipes are-fixed'in andthrOtighthe -respective endplateslland l2 in coaxial relation withthe shell'lll and consequently centrally of the latter. Promotive of gas-expansion and consequent cooling andinhibitive ofthe development of undesirable eddies and retarding circulatory efiects, the inlet pipe 13 is extended interiorly of the-shell and beyond the plate ll-therebyintersected a considerable distance, on the order of six'inches, to provide an annular chamber or space thereabout and withintheinput end of the shell 10, within which space the-gases discharged from 1 the pipe 13 may expand and circulate without congesting the area adjacent the discharge end of the pipe.

For a considerable distance frorn the delivery end of the pipe 1-3 the-interior of the shell 10 is open ,and unobstructed toprovidean expansion chamber wherein'the exhaust gases are cooled, consequently reduced in volume, and to some degree mufiled astheir velocityis retarded, but inwardly from; the plate 12 at the discharge end of the-shell, and at a preferred distance of about twelve inches from said plate, a baffle 17 closes alrnost entirely across and transversely of the shell. The'baflle 17 is a flat plate formed to close marginally againstthe interiorwalls of the shell10 when said bafile is disposed transversely of the shell at a moderateangle to theshell longitudinal axis such as advances the lower margin of the baille toward the tailpipe 1'4'beyond the upper bajtile margin, as is clearly shown inFigure 2, and the lower margin 18 of said baflle17 is cut back to a straightfline chordal of the shell to leave a relatively narrow segmentalunobstructed passage within the shelljhelow said margin. The battle 17 is further characterized by circular openings 19, preferably five in number and patterned substantiallyas illustrated with one oftheopeningsregistered longitudinally of the shell with the bore of the tailpipe-14, and thebaflie 17 isfixed to and within said shell 10, as by means of Welding orother atta chm ent of the bafile upper margin to an angular-bracket20secured to the interior wall of the shell 10, thusto rigidly support the battle in its inclined disposition and spaced relation from the end plate 12.

Significant to the satisfactory performance of the improvement, an extension 14' of the tailpipe 14 intrudes within the shell 10 from the plate 12 a distance on the order of six inches, or one-half the spacing between the plate 12 and zone of baffle 17 attachment to the shell, to terminate in an open and unobstructed end within the shell, and said tailpipei extension 14' is intersected by a plurality of relatively small openings 21 dispersed through and about the wall area of said extension within the shell to the number of twenty-six or twenty-seven and in substantially the pattern represented by the'drawings, said openings 21 precluding the entrapment of any gases in the space within the shell about the tailpipe extension 14 and facilitating discharge of the cooled and expanded gases from the shell interior in a manner to suppress pulsations and resonant vibrations.

While the shell 10 will most commonly and economically be a right cylinder, as represented by Figures 3 and 4, there are situations wherein a shell oval or elliptical in cross section is preferred, and Figures 5 and 6 represent the obvious adaptation of the principles of the invention to shells of such form in either vertical or horizontal disposition of the oval Shell long axis.

Mufflers constructed as shown and described are inexpensive of production, durable in use, and have proved to be highly efficient in the cooling and silencing of exhaust gases from internal combustion engines. The factors operating to promote the unusually high cooling and silencing efliciency of the improved muffler obviously derive from the novel construction, arrangement, and correlation of the very few simple elements comprised in the unit and manifestly include suppression of resonance as a consequence of the baflle arrangement and tailpipe extension. These factors are not so well understood as to permit of detailed explanation herein and are deemed to be unimportant to an understanding of the construction and use of the improved mufller, it being manifest that the illustration and foregoing description are adequate to permit those of even moderate skill to practice the invention as set forth.

Since changes, variations, and modifications in the form, construction, and arrangement of the elements shown and described may be had without departing from the spirit of my invention, I wish to be understood as being limited solely by the scope of the appended claims, rather than by any details of the illustrative showing and foregoing description.

I claim as my invention- 1. An exhaust gas muffler comprising an elongated, hollow shell closed at its ends, an open-ended, otherwise, imperforate, inlet pipe centrally through one closed end of the shell for delivery interiorly of the shell well beyond the end thereby intersected, an open-end tailpipe centrally through the other closed end of the shell for major intake at some distance from the end thereby intersected, a single, apertured baffle inclined to the longitudinal axis of the shell transversely within and substantially obstructing the shell interior more nearly adjacent said tailpipe than said inlet pipe, whereby to divide the shell interior into a greater inlet compartment and a lesser outlet compartment, said baille being the only barrier to direct free flow of gas through the shell between the inlet pipe and tailpipe, and a margin at the edge of said bafile most nearly adjacent the tailpipe spaced from the shell wall to provide a passage interconnecting said compartments. 7 a

2. An exhaust gas mufller comprising an elongated, hollow shell closed at its ends, an open-ended, otherwise imperforate, inlet pipe centrally through and projecting interiorly of the shell beyond one closed end of the shell for delivery interiorly of the shell well beyond the end thereby intersected, a tailpipe centrally through the other closed end of the shell, an open-end, apertured extension of said tailpipe interiorly of the shell for major intake 4 at some distance from the adjacent end of the shell, a single, apertured baflle inclined to the longitudinal axis of the shell closing transversely within and substantially obstructing the shell interior spacedly adjacent said extension, whereby to divide the shell interior into a greater inlet compartment containing the inlet pipe projection and a lesser outlet compartment containing the tailpipe extension, said bafile being the only barrier to direct free flow of gas through the shell between the inlet pipe and tailpipe, and a passage interconnecting said compartments between the shell wall and the edge of said battle most nearly adjacent said extension.

3. An exhaust gas muiller comprising an elongated, hollow shell closed at its ends, a straight, imperforate, inlet pipe open at both ends centrally through and projecting interiorly of the shell beyond one closed end of the shell for delivery interiorly of the shell well beyond the end thereby intersected, means at the exterior end of said pipe for connecting the latter as a continuation of and to receive the delivery from an exhaust gas flow line, a tailpipe centrally through the other closed end of said shell, an open-end, apertured extension of said tailpipe coaxial with and interiorly of the shell for major intake at some distance from the adjacentend of the shell, a single, apertured baflle inclined to the longitudinal axis of the shell closing transversely within and substantially obstructing the shell interior spacedly adjacent said extension, whereby to divide the shell interior into a greater inlet compartment containing the inlet pipe projection and a lesser outlet compartment containing the tailpipe extension, said bafile being the only barrier to direct free flow of gas through the shell between the inlet pipe and tailpipe, and a passage interconnecting said compartments between the shell wall and a free margin of said baflle at the edge of the latter most nearly adjacent said extension.

4. In an exhaust gas mufiler having an elongated, hollow shell closed at its ends, an inlet pipe centrally through one closed end of the shell, a tailpipe centrally through the other closed end of the shell, and means for operatively associating the exterior end of said inlet pipe with an exhaust gas flow line, the improvements which comprise a straight, imperforate, open-end projection of said inlet pipe interiorly of the shell a substantial distance beyond the shell end thereby intersected, a straight, apertured, open-end extension of the tailpipe interiorly of the shell a substantial distance beyond the shell end intersected by the tailpipe, a single, flat, apertured baffle inclined to the longitudinal axis of the shell closing transversely within and substantially obstructing the shell interior in a spacing from the inner end of the tailpipe extension, said batlle being the only barrier to direct free flow of gas through the shell between the inlet pipe and tailpipe, and a margin at the edge of the baflle most nearly adjacent the tailpipe divergent from the adjacent shell wall to provide a passage interconnecting the shell compartments at the opposite sides of the bathe.

References Cited in the file of this patent I UNITED STATES PATENTS 1,021,254 Larkins Mar. 26, 1912 1,061,775 Newton May 13, 1913 2,241,010 Chipley May 6, 1941 2,287,412 Bourne June 23, 1942 2,392,247 Katcher Ian. 1, 1946 FOREIGN PATENTS 729,253 France Apr. 25, 1932 646,735 Germany June 19, 1937 726,028 Germany Oct. 5, 1942 

